JEE Main 2019ChemistryIonic EquilibriumHardMCQ

JEE Main 2019 — Ionic Equilibrium Question with Solution

JEE Main 2019 (09 Jan Shift 1)

Question

20 ml of 0.1 M H2SO4  solution is added to 30 mL of 0.2 M NH4OH solution. The pH of the resultant mixture is: pkb of NH4OH=4.7

Choose an option

Show full solutionCorrect option: D
Correct answer
D9.0

Step-by-step explanation

Millimoles of H2SO4=20×0.1=2

Millimoles of NH4OH=30×0.2=6



Hence, the solution will act as a basic buffer.

pOH=pKb+logsaltBase

NH4+=2×NH42SO4;         NH4+=4

pOH=pKb+logNH4+NH3

=4.7+log42

=4.7+0.3010=5.010

pH=14-pOH=9

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About this question

This is a previous-year question from JEE Main 2019, covering the Ionic Equilibrium chapter of Chemistry. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.